The purpose of this study is to determine whether high dose intravenous (injected into a vein) immunoglobulin (naturally-occurring antibodies) is more effective than placebo (inactive substance) in restoring visual function in patients with optic neuritis. In December 1997, the director of the National Eye Institute recommended that this trial be stopped because of futility. An interim analysis for efficacy had shown that there was little likelihood that continuing the study would lead to a positive result [primary outcome: recovery of visual function]. No additional patients were enrolled, and no additional infusions were given. Bayer Pharmaceuticals [supplier of IVIG and placebo] have indicated that they may wish to provide additional funds to allow us to collect twelve month follow up on all enrolled patients. There is some preliminary evidence from the secondary analysis done at the time of the NEI review that one or more of the secondary outcome measures may show a "hint of efficacy" [e.g. visual fields and electrophysological studies]. Requests for additional NEI funding to assist with data analysis and study determination has been submitted along with a parallel submission to Bayer requesting funding to allow twelve-month follow up. Abstracts and manuscripts are being prepared.